nH2 = 0,1 mol
Đặt nNa = x (mol); nBa = y (mol); ( x, y > 0 )
2Na + 2H2O \(\rightarrow\) 2NaOH + H2 (1)
x...........................x...........0,5x
Ba + 2H2O \(\rightarrow\) Ba(OH)2 + H2 (2)
y........................y................y
Từ (1)(2) ta có hệ pt
\(\left\{{}\begin{matrix}23x+137y=9,15\\0,5x+y=0,1\end{matrix}\right.\)
\(\Rightarrow\) \(\left\{{}\begin{matrix}x=0,1\\y=0,05\end{matrix}\right.\)
\(\Rightarrow\) %Na = \(\dfrac{0,1.23.100}{9,15}\)\(\approx\) 25,1%
\(\Rightarrow\) %Ba = \(\dfrac{0,05.137.100}{9,15}\) \(\approx\) 74,9%
\(\Rightarrow\) CM NaOH = \(\dfrac{0,1}{0,3}\) = \(\dfrac{1}{3}\) (M)
\(\Rightarrow\) CM Ba(OH)2 = \(\dfrac{0,05}{0,3}\) = \(\dfrac{1}{6}\) (M)
2Na+2H2O ---------> 2NaOH+ H2
a........ a..........................a.......0.5a
Ba + 2H2O ----------> Ba(OH)2+ H2
b........2b............................b..........b
nH2=0.1 mol
Đặt a, b lần lượt là số mol của Na, Ba
Ta có PTKLhh=23a+137b=9.15 (I)
Và nH2=0.5a+b=0.1 (II)
Giải hệ pt (I), (II) =>a=0.1 mol
b=0.05 mol
Do đó %mNa=\(\dfrac{23\cdot0.1\cdot100}{9.15}\)=25.14%
%mBa=100%-25.14%= 74.86%
b)CmNaOH=\(\dfrac{0.1}{0.3}\)=0.33M
CmBa(OH)2=\(\dfrac{0.05}{0.3}\)=0.17 mol
c)NaOH + HCl---------> NaCl +H2O
0.1............0.1
Ba(OH)2+2HCl----------> BaCl2+ 2H2O
0.05...........0.1
=>VHCl=(0.1+0.1)/2=0.1 lít
